Communication control device connected between an image forming apparatus and a host system

ABSTRACT

A communication control device connected between an image forming apparatus and a communication line in an image forming apparatus supervising system which connects the image forming apparatus and a host machine by the communication line. Assume that particular data of an image forming apparatus and updated day by day should be read periodically. Then, even when the power supply to the image forming apparatus is shut off, a host machine can access the apparatus to read the data which should be read periodically, and receive it. In addition, the data can be preserved until the next time for reading.

This application is a Continuation of application Ser. No. 08/694,029,filed on Aug. 8, 1996, now U.S. Pat. No. 5,812,900, which is aContinuation of application Ser. No. 08/159,480, filed on Nov. 30, 1993,now U.S. Pat. No. 5,583,615.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image forming apparatus supervisingsystem connecting an image forming apparatus and a host machine via acommunication line and, more particularly, to a communication controldevice connected between the image forming apparatus and thecommunication line for controlling their communication.

2. Discussion of the Background

An image forming apparatus supervising system of the type described mayconnect a plurality of copiers or similar image forming apparatuses to ahost machine located at, for example, a remote service center over aswitched telephone network or similar communication line. This kind ofsystem is disclosed in Japanese Patent Laid-Open Publication (Kokai)Nos. 257155/1990, 259666/1990, and 196053/1991 by way of example. Insuch a system, a single host machine controls a plurality of remoteimage forming apparatuses collectively so as to add up the conditions ofthe individual apparatuses relating to use and to effect maintenance.The conditions relating to use include the number of copies produced.Regarding maintenance, each image forming apparatus may call the hostmachine automatically after self-diagnosis, or the host machine mayaccess the individual apparatuses to adjust various portions thereof.Today, it is a common practice with this kind of system to read acounter (generally the number of copies produced) built in each imageforming apparatus by remote control, thereby charging the user of theapparatus for a maintenance contract.

However, the problem with the conventional supervising system is thateven when the image forming apparatus and the host machine are connectedby a communication line, the host machine cannot read theabove-mentioned particular data out of the apparatus if the power supplyto the apparatus is shut off. As a result, the time when the hostmachine can read the data is limited. For example, although the hostmachine should preferably read the data out of the image formingapparatus at nighttime during which communication cost is low andtraffic is light, i.e., a high connection rate is achievable, the powersupply to the apparatus is often shut off at nighttime.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide acommunication control device for an image forming apparatus supervisingsystem which allows particular data to be sent from an image formingapparatus to a host machine even when the power supply to the apparatusis shut off.

In accordance with the present invention, a communication control deviceconnected between an image forming apparatus and a communication line inan image forming apparatus supervising system which connects the imageforming apparatus and a host machine by the communication line comprisesa particular data receiving section for receiving particular data fromthe image forming apparatus periodically, a first storage for storingthe particular data received by the particular data receiving section,and a second storage for storing the particular data transferred fromthe first storage. The device is capable of reading the particular dataout of the second storage when connected to the host machine via thecommunication line.

Also, in accordance with the present invention, a communication controldevice connected between an image forming apparatus and a communicationline in an image forming apparatus supervising system of the typedescribed comprises a particular data receiving section for receivingparticular data from the image forming apparatus periodically, a firststorage for storing the particular data received by the particular datareceiving section, a second storage for storing the particular datatransferred from the first storage, and a transmitting section forsending the particular data stored in the second storage to the hostmachine periodically.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription taken with the accompanying drawings in which:

FIG. 1 is a section of a copier belonging to a family of image formingapparatuses to which the present invention is applicable;

FIG. 2 shows a specific layout of a display and operation board providedon the copier of FIG. 1;

FIG. 3 is a fragmentary enlarged view of the display and operationboard;

FIG. 4 is a block diagram schematically showing a specific constructionof an image forming apparatus supervising system with which acommunication control device embodying the present invention ispracticable:

FIG. 5 is a block diagram schematically showing a specific constructionof a control device shown in FIG. 4;

FIG. 6 is a block diagram schematically showing a specific constructionof a host machine shown in FIG. 4;

FIG. 7 is a schematic block diagram showing a specific construction of acontrol system incorporated in a copier of FIG. 4;

FIGS. 8A-8C each show a particular communication sequence particular tothe supervising system and relating to a remote report;

FIGS. 9A-9C each show a particular communication sequence alsoparticular to the supervising system and relating to an access from thehost machine to the copier;

FIGS. 10A-10C each show a particular sequence also particular to thesupervising system and relating to an access from the host machine tothe communication control device;

FIG. 11 shows a communication sequence in which the communicationcontrol device accesses the copier without the intermediary of the hostmachine;

FIG. 12 shows a communication sequence also particular to thesupervising system and implementing the transfer of a total countervalue;

FIG. 13 shows another communication sequence relating to the transfer ofa total counter value;

FIG. 14 is a table listing parameters set in the communication controldevice shown in FIG. 5;

FIGS. 15A-15C each show a particular data format to be sent by a remotereport;

FIGS. 16, 17 and 18 show respectively a read process data format, awrite process data format, and an execute process data format with whichthe host machine of FIG. 4 can access the copier;

FIG. 19A-19C each show a specific data format with which the hostmachine can access the communication control device;

FIG. 20 shows a specific data format for implementing the access fromthe communication control device to the copier;

FIG. 21 is a flowchart demonstrating a main routine which a CPU (CentralProcessing Unit) built in the copier executes for report control:

FIGS. 22, 23 and 24 are flowcharts respectively representative of aremote report key subroutine, a self-diagnosis error subroutine, and aprecaution subroutine included in the main routine of FIG. 21;

FIG. 25 is a flowchart representative of a main routine which the CPU ofthe copier executes when accessed by the communication control device;

FIGS. 26, 27 and 28 are flowcharts showing respectively a read processsubroutine, a write process subroutine, and an execute processsubroutine included in the main routine of FIG. 25;

FIG. 29 is a flowchart demonstrating total counter value communicationcontrol associated with FIG. 12 and executed by the communicationcontrol device;

FIG. 30 is a flowchart showing total counter value communication controlassociated with FIG. 13 and executed by the communication controldevice;

FIGS. 31, 32 and 33 are flowcharts showing respectively a total countervalue collection subroutine, a total counter value transfer subroutine,and a total counter value report subroutine included in the procedure ofFIGS. 29 or 30;

FIG. 34 is a flowchart representative of initialization executed by thecommunication control device;

FIG. 35 shows a communication sequence in an idle state and particularto a case wherein five copiers are connected to the communicationcontrol device;

FIG. 36 shows a communication sequence in which a copier provided withan address 2 has a remote report text to send;

FIG. 37 shows a communication sequence in which the communicationcontrol device sends a text representative of the result of report to acopier designated by an address 5;

FIG. 38 shows a communication sequence between the communication controldevice and a copier with an address 3 to occur when the host machine ofthe control device accesses the copier; and

FIGS. 39 and 40 each show a particular communication sequence betweenthe communication control device and the copiers to occur in the eventof total counter value transfer which is performed periodically.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 of the drawings, an image forming apparatus to whicha control system implemented with the present invention is applicable isshown and implemented as a copier by way of example. As shown, thecopier, generally 1, is an electrophotographic plain paper copier (PPC)and is generally made up of a copier body 2 and an automatic documentfeeder (ADF) 3 mounted on the top of the body 2. A tray 4 for manualpaper insertion and a mass paper feed unit 5 are provided on one side ofthe copier body 2, while a copy tray 6 is provided on the other side. Adocument tray 7 is provided on the ADF 3 and includes a document setsensor 8. Arranged in the copier body 2 are a scanner section 10, animage forming section 11, a paper feed section 12, an image fixing andpaper discharging section 13, a paper turning section 14, a two-sidedcopy unit 15, etc.

The scanner section 10 has a glass platen 21, a first scanner 24 made upof a lamp 22 and a first mirror 23, a second scanner 27 made up of asecond mirror 25 and a third mirror 26, a third scanner 30 made up of afourth mirror 28 and a fifth mirror 29, a sixth mirror 31, and a lens32. The image forming section 11 includes a photoconductive drum 35.Arranged around the drum 35 are a quenching lamp 36, a main charger 37,an eraser 38, a potential sensor 39, a developing unit 40 on which atoner cartridge 41 is removably mounted, a pretransfer charger 42, atransfer charger 43, a paper separation charger 44, a photosensor or Psensor, as sometimes referred to hereinafter, 45, and a cleaning unit46. A registration roller pair 47 is located on a paper transport pathupstream of an image transfer position, while a transport belt 48 islocated on the transport path downstream of the image transfer position.

The paper feed section 12 has a first to a fourth removable tray 51-54each being loaded with a stack of papers of particular size. A first toa fourth pick-up paper feed units 55-58 are associated with the trays51-54, respectively. Likewise, a paper feed unit 59 is associated withthe manual paper tray 4 and a large capacity tray (LCT) 60. A righttransport section 61, a left transport section 62 and a horizontaltransport section 63 are provided for transporting papers selectivelyfed out of the units 55-59 and 15 toward the registration roller pair47. The fixing and discharging section 13 has a fixing unit 65 and agroup of discharge rollers 66. The paper turning section has a group ofturn-over rollers 67.

The operation of the copier 1 will be outlined hereinafter. The drum 35is mounted on a shaft, not shown, and rotatable in a direction indicatedby an arrow A in the figure in response to a copy command or similarcommand. A document fed to the glass platen 21 by the ADF 3 is scannedby the first scanner 24. The resulting imagewise reflection from thedocument is focused onto the drum 35 via the mirrors 23, 25 and 26, lens32, and mirrors 29 and 31. The surface of the drum 35 has been chargedby the main charger 37 beforehand. As a result, a latent imagerepresentative of the document is electrostatically formed on the drum35. The eraser 38 illuminates needless portions of the drum 35 so as totrim the latent image such that it is suitable for a paper or aprojection image. To reproduce the document in a 1:1 magnification, thedrum 35 and the first scanner 24 are driven at the same speed as eachother. The developing unit 40 develops the latent image to produce acorresponding toner image. At this instant, a potential (bias voltagefor development) is applied to the developing unit 40 to render a darkimage or a light image, as desired.

A paper is fed from a desired one of the trays 51-54, 4 and 60 andtwo-sided copy unit 15 by associated one of the feed units 55-59 at apredetermined timing. The paper is routed through the right transportsection 61, the left transport section 62, the horizontal transportsection 63 and so forth toward the register roller pair 47 which areheld in a stop then. The register roller pair 47 is driven at such atiming that the leading edge of the paper meets the leading edge of thetoner image carried on the drum 35. As a result, the toner image istransferred from the drum 35 to the paper by the pretransfer charger 42and transfer charger 43. At this instant, since the surface of the drum35 is extremely smooth and causes the paper 40 adhere closely thereto,the separation charger 44 lowers the potential and, therefore, theadhesion of the paper.

After the paper has been separated from the drum 35 by a separator, notshown, it is transported to the fixing unit 65 by the transport belt 48.The fixing unit 65 fixes the toner image on the paper by heat andpressure. Finally, the paper, or copy, is driven out to the copy tray 6by the discharge rollers 66. In a two-sided copy mode, the papercarrying the image on one side thereof is driven into the turningsection 14, turned over, and then delivered to the two-sided copy unit15. This paper is refed from the unit 15 to the image forming section 11when the next document image is to be reproduced. After the imagetransfer, a brush and a blade included in the cleaning unit 46 removethe toner remaining on the surface of the drum 35. Subsequently, thequenching lamp 36 regularizes the surface potential of the drum 35. Acontrol circuit, which will be described, controls the proceduredescribed above mainly in response to pulses synchronous to the rotationof the drum 35 or reference pulses used to drive the drum 35.

FIG. 2 shows a specific configuration of an operation and display board70 provided on the copier. As shown, the board 70 includes a guidancedisplay 71 and a pattern display 72 which are located at the center andimplemented by LCD (Liquid Crystal Display) panels. A number of keys arearranged at both sides and in front of the displays 71 and 72.Specifically, a start key 73, an interrupt key 74, a preheat key 75, amode clear/preheat key 76, numeral keys 77, a clear/stop key 78, a timerkey 79, a program key 80, an enter key 81, and a guidance key 82 arelocated at the right-hand side. A remote report key 83, a sorter key 84,a two-side key 85, a page continuous key 86, an erase key 87, a paperpriority magnification change key 88, a zoom key 89, a margin adjust key90, a center key 91 and a size priority magnification key 92, are alsoprovided. Arranged in front of the displays 71 and 72 are a reduce key93, an enlarge key 94, an 1:1 key 95, a paper select key 96, an autopaper select key 97, a density adjust key 98, and an auto density key99. When the remote report key 83 is pressed to effect a remote report,an indicator, or LED (Light Emitting Diode) 83a is turned on.

FIG. 3 shows the pattern display 72 in an enlarged scale. As shown, anumber of copies set D1, a number of copies produced D2, a running stateD3, a density D4, a misfeed position D5, a short paper supply D6, amisfeed D7, a remote communication error D8, a short toner supply D9, ashort paper D10, a paper selection/size/orientation D11, and 9magnification display D12 are displayed in patterns.

The guidance display 71, FIG. 2, displays various kinds of messages formanipulation and alarm. The display and operation board 70 ischaracterized by the remote report key 83 and remote communication errorindicator D8. The key 83 is pressed by the user to request a servicewhile the indicator D8 alerts the user to a communication error.However, the remote report key 83 is not essential. For example, otherparticular keys may be pressed in a particular order or for a particularduration or may be pressed at the same time to implement the function ofthe key 83.

Referring to FIG. 4, a system for supervising image forming apparatusescollectively and implemented with a communication control deviceembodying the present invention will be described. As shown, the systemincludes a host machine 16 situated at a service center, copiers (PPC)or similar image forming apparatuses 1 installed at individual users'stations, and a telephone network 17 connecting the host machine 16 andcopiers 1. At each user's station, the copier 1 is connected to acommunication control device 18 which controls the communication of thecopier 1 with the host machine 16. A telephone set 19 and/or a facsimileapparatus 20 is connectable to the control device 18. The control device18 is inserted in the user's existing communication line. While aplurality of copiers 1 are shown as being connected to the controldevice 18, only one copier may, of course, be connected thereto. Thecopiers 1 may be of the same type or of different types and may even bereplaced with, for example printers. Here, assume that five copiers 1 ata maximum can be connected to the control device 18 by way of example.The control device 18 and the copiers 1 are connected by a multi-droparrangement based on an RS-485 standard.

The communication between the control device 18 and each copier 1 iscontrolled by a basic data transmission control procedure. Specifically,the control device 18 can communicate with any one of the associatedcopiers 1 by setting up a data link on the basis of a centralizedcontrol polling/selecting system in which the device 18 plays the roleof a control station. Each copier is provided with an address set switchfor entering a value particular to the copier. Hence, the copiers 1 areeach provided with a particular polling address and a particularselecting address.

FIG. 5 shows a specific construction of the control device 18. As shown,a signal from the subscriber line 17 is applied to a switching section180. If the communication from the subscriber line 17 is addressed tothe telephone set 19 (or facsimile apparatus 20, FIG. 4), the switchingsection 180 connects it to the telephone set 19 (or facsimile apparatus20). If the communication is originated by the host machine 16, theswitching section 180 connects it to a modem 181 associated with thesubscriber line 17. Further, the control device 18 communicates with thecopier 1 via a communication interface 183 which is implemented by atransceiver for the RS-485 application. Such control and processing areexecuted mainly by a CPU (Central Processing Unit) 184 according to acontrol program stored in a ROM (Read Only Memory) 185. A RAM (RandomAccess Memory) 186 is used to store interim results of processing and tostore a text to be sent for a moment. Also, parameters necessary for thecontrol device 18 to operate are written in the RAM 186 from the hostmachine 16. The control device 18 is continuously powered for 24 hoursto be communicable with the host machine 16 anytime. In addition, theRAM 186 is backed up by a battery 187 to prevent the parameters storedin the RAM 186 from being lost due to accidental power shut-off. Thecontrol device 18 further includes a timepiece 188 and a switch 189which allows a total counter value to be automatically sent to the hostmachine 16, as will be described specifically later.

FIG. 6 shows a specific construction of the host machine 16. As shown,the host machine 16 has a host computer 160 for executing various kindsof processing, a magnetic disk or similar recording medium 161 forstoring supervisory data as well as other data, a display 162, akeyboard 163, a printer 164 for outputting the supervisory data, and amodem 165 for connecting the machine 16 to the subscriber line ortelephone network 17.

FIG. 7 shows a control system incorporated in the copier 1, FIG. 1. Asshown, the copier body 2 is controlled mainly by the CPU 100 accordingto a control program and data stored in the ROM 101. A RAM 102 is usedto store the interim results of processing. An analog-to-digitalconverter (ADC) 103 is used to input a voltage to be applied to the lamp22, the emission voltage and reception voltage of the P sensor 45, theoutput of the potential sensor 39, the output of the ADF sensor 8, theoutput of a sensor responsive to the quantity of light issuing from thelamp 22, the output of a sensor responsive to a current flowing throughthe drum 35, the voltage of a thermistor included in the fixing unit 65,etc. An optics control unit 104 controls the scanner section 10, FIG. 1.A high-tension power source unit 105 generates high voltages to beapplied to the main charger 37, separation charger 44, transfer charger43 and pretransfer charger (PTC) 42, and a bias voltage to be applied tothe developing roller of the developing unit 40.

A motor control unit 106 controls a main motor which drives the drum 35and the rollers included in the paper feed units and transport sections.A heater control unit 107 controls the current supply to a heater whichheats the fixing roller of the fixing unit 65, thereby confining thesurface temperature of the roller in a predetermined range. A sensorsensitivity control unit 108 is used to change the reception gains ofthe lamp sensor, ADF sensor 8 and P sensor 45 as well as the emissionvoltage of the LED of the P sensor 45. A communication interface unit109 allows the control system to communicate with the control device 18therethrough. An address set switch 110 is accessible for setting anaddress particular to the copier within the range of "1" to "5". Acommunication permit/inhibit switch 111 is operated to permit or inhibitthe communication of the control system with the control device 18.Implemented by a dip switch, the switch 111 is turned on by a servicemanwhen the copier with the switch 111 is connected to the image formingapparatus control system (remote diagnosis system); the user, inprinciple, is inhibited from touching it. Therefore, the switch 111remains in an ON state when the copier is held in connection with theremote diagnosis system.

The operation of the embodiment will be described with reference mainlyto FIG. 8A and onward. To begin with, a reference will be made to FIGS.8A-8C and 4 for describing the remote reporting function.

To effect a remote report, the remote report key 83 provided on theoperation panel board 70, FIG. 2, is pressed. Then, as shown in FIG. 8A,the copier 1 sends remote report data to the control device 18. Inresponse, the control device 18 dials a telephone number assigned to thehost machine 16 and stored therein beforehand, thereby sending theremote report data to the machine 16. The host machine 16 is usuallylocated at a service center. At this instant, the control device 18sends, among a plurality of kinds of data received from the copier 1,only the data of the kinds set therein beforehand to the host machine16. Such particular data can be set in the control device 18 by the hostmachine 16 via the telephone network 17. On sending all thepredetermined data to the host machine 16, the control device 18 informsthe copier 1 of the result of communication of the device 18 with thehost machine 16. This allows the copier 1 to see if the communicationwas successful or failed due to some error.

It is a common practice to provide a copier with a self-diagnosisfunction. When the copier is in a dangerous condition or cannot beoperated, e.g., when the fixing temperature is unusual or when any ofthe portions to be adjusted by electronic volumes cannot be adjusted, acopier with a self-diagnosis function alerts the user or a servicemanwith "Error" or "Serviceman Call". As shown in FIG. 8B, when the copier1 finds an error occurred therein with the self-diagnosis function, italso sends remote report data to the control device 18. In response, thecontrol device 18 sends the remote report data resulted fromself-diagnosis to the host machine 16 and, on the end of communication,returns the result of communication to the copier 1.

Assume that the copier 1 has determined that it is nearly abnormal, ifnot abnormal, by self-diagnosis and, therefore, that maintenance shouldpreferably be effected. Then, as shown in FIG. 8C, the copier 1 sendsremote report data to the control device 18 for precaution. In the caseof the remote report due to an error, the copier will, of course, havebeen brought to an unusable state. However, in the case of the remotereport for precaution, the copier is left in a usable condition; evenwhen a communication is under way, it will perform a copying operationwhen a document is set and the start key is pressed. At this instant,the communication may be interrupted if the copying operation willincrease the load on the, controller of the copier 1 excessively or ifthe content included in the transmission data will be changed by thecopying operation. Generally, the remote report data for precaution isnot urgent. Hence, an arrangement may be made such that the controldevice 18 which received such data calls the host machine 16 in a timezone suitable for communication, instead of calling it immediately. Thetime zone suitable for communication may be one in which the telephoneset 19 and facsimile apparatus 20 are not used often or one in which thetraffic of the network 17 is light. The time when the control device 18should call the host machine 16 is set in the former by the latter viathe network 17 and can be determined by referencing the timepiece 188,FIG. 5. Regarding the remote report for precaution, as distinguishedfrom the other remote reports, the control device 18 does not send theresult of communication to the copier 1.

How the host machine 16 accesses the copier 1 will be described withreference to FIGS. 9A-9C. The accesses from the host machine 16 to thecopier 1 are generally classified into three kinds in respect of object,i.e., a read request, a write request and an execute request. The readrequest refers to processing for reading logging data, various setvalues, various sensor outputs and so forth out of the copier 1. Thewrite request refers to processing for sending data to the copier 1 toupdate the set values as well as the others. With the execute request,the host machine 16 causes the copier 1 to perform tests itself. In anyof the procedures shown in FIGS. 9A-9C, the host machine 16 dials thecontrol device 18 to which a desired one of the copiers 1 is connected,and then sends request data. On receiving the request data, the controldevice 18 sends them to the copier 1 of interest. In response, thecopier 1 processes the content of the request and then sends a responseto the request to the control device 18. The control device 18 sends theresponse to the host machine 16, thereby completing a single processunit.

As shown in FIGS. 10A-10C, the host machine 16 accesses the controldevice 18 with any one of a read request, a write request, and anexecute request, as in the case of the access to the copier 1. With theread request, the host machine 16 causes the control device 18 to readparameters set therein and statuses thereof and read, when the device 18has read information out of the copier 1 and stored therein beforehand,such information. The write request refers to processing for sendingparameters meant for the control device 18 from the host machine 16 tothe device 18 and setting them in the device 18. With the executerequest, the host machine 16 causes the control device 18 to performfunction checking and other testing operations.

FIG. 11 shows a procedure in which the control device 18 accesses thecopier 1 without the intermediary of the host machine 16. This procedureallows the control device 18 to read information out of the copier 1 andstore them in itself. The host machine 16 can read the information outof the control device 18 later.

Referring to FIG. 12, a communication procedure associated withparticular data will be described. It is a common practice with a copierto use the content of a counter representative of the total number ofcopies produced (referred to as a total counter value hereinafter) asparticular data for maintenance. As the copier 1 sends the total countervalue to the control device 18 periodically, the host machine 16 can seeit even when the copier 1 is unable to communicate, e.g., when the powersupply to the copier 1 is shut off. This can be done since the controldevice 18 has a function of reading information out of the copier 1 andstoring them in itself, as stated previously. The control device 18 hasa timer for the collection of total counter values and which is includedin the timepiece 188, FIG. 5. The parameters set in the control device18 include a time for collecting total counter values. When the time forcollecting total counter values is reached as determined by theabove-mentioned timer, the control device 18 sends a read request to allthe copiers 1 connected thereto one after another every day, therebyreading their total counter values sequentially.

On receiving a new total counter value from any one of the copiers 1,the control device 18 updates the value read the day before and storesthe updated value in the area of the RAM 186 assigned to total countervalues (referred to as a memory A hereinafter). When the copier 1 whichreceived the read request is unable to communicate, e.g., when the powersupply thereto is shut off, the control device 18 goes to the nextcopier 1, skipping it. After sending the read request to all the copiers1, the control device 18 again sends a read request to the copiers 1which failed to receive the request. Nighttime is selected as the timefor collecting total counter values since the copiers 1 are usually notexpected to be powered at nighttime. Then, just after the power supplyto the copiers 1 has been sequentially set up in the morning, the abovecommunication is executed while the idling or adjustment of the copiers1 are under way. Further, when the copier 1 which received the readrequest from the control device 18 does return an answer, the device 18sends the read request to the copier 1 repetitively until it receives aresponse. Assuming that a single copier 1 is connected to the controldevice 18, the device 18 sends the read request every fifteen seconds.

The parameters set in the control device 18 also include a date fortransferring the total counter values. When this date is reached asdetermined by a total counter value transfer timer (included in thetimepiece 188), the control device 18 transfers the total counter valuesfrom the memory A of the RAM 186 to a total counter value transfer area(referred to as a memory B hereinafter) also included in the RAM 186.Usually, the total counter transfer date is set at, for example, themonthly add-up day of the maintenance contract. This allows the totalcounter values to be stored in the RAM 186 on every add-up day even whenthe copiers 1 are unable to communicate. The total counter values storedin the memory B of the control device 18 are sent to the host machine 16by either of two different methods, i.e., a method which causes the hostmachine 16 to access the control device 18 periodically, e.g., on themonthly add-up day, and a method which causes the control device 18 tosend the total counter values to the host machine 16 automatically whena date set in the device 18 for reporting the total counter valuesautomatically is reached. One of such two methods is selected by thepreviously mentioned switch 189, FIG. 5. While the switch 189 is in anON state, the control device 18 dials the host machine 16 automaticallywhen the automatic report date set therein is reached. When the switch189 is in an OFF state, the control device 18 simply awaits an accessfrom the host machine 16. It is to be noted that the total counter valuedescribed above is a mere example of particular data and may be replacedwith any other data or may be sent together with other data.

Another specific procedure for sending particular data is shown in FIG.13. As shown, assume that the control device 18 has collected a totalcounter value from a given copier 1 within a predetermined period oftime after the total counter value transfer date or has not received iteven after the predetermined period of time. Then, the control device 18transfers the total counter value from the memory A to the memory B.Further, triggered by the transfer of the total counter value, thecontrol device 18 sends the value to the host machine 16.

FIG. 14 is a table listing the parameters set in the control device 18.As shown, a type number and a serial number assigned to each copier 1are registered at the control device 18. When the copiers 1 communicatewith the control device 18, they send the type numbers and serialnumbers thereof to the device 18 together with data. Also, when the hostmachine 16 accesses the copiers 1, the type numbers and serial numbersare used to determine the addresses of the copier 1. The telephonenumber of a destination, the number of times and interval of redialing,and the kinds of data to be sent to the host machine 16 are alsoregistered at the control device 18 on the basis of the reason for theremote report. Regarding the remote report for precaution, the time whenit is effected is also registered. A checksum is added to each parameterblock and used to detect an occurrence that the value of the parameteris changed or lost due to the malfunction of the control device 18 orthe consumption of the back-up battery 187. In the illustrativeembodiment, such parameters are written to the control device 18 by thehost machine 16 via the network 17. Alternatively, a portable apparatusfor setting the parameters may be directly connected to the controldevice 18 at the user's station, or extra setting means may be providedon the control device 18.

FIGS. 15A-15C show specific data formats for implementing a remotereport. The format of FIG. 15A is used for the communication from thecopier 1 to the control device 18. As shown, the format is headed by afield assigned to a code representative of the reason for the remotereport, i.e., whether the remote report is based on the remote reportkey, error found by self-diagnosis, or precaution. This reason for theremote report is followed by information relating to the inside of thecopier. States of a copier included in the format include the conditionsof toner, oil, paper and other supplies, the outputs of various sensors,the set values of various adjustable portions, and the connection statesof units. The data format shown in FIG. 15B implements the communicationfrom the control device 18 to the host machine 16. As shown, the controldevice 18 sends, before the data received from the copier 1, a typenumber field and a serial number field for specifying the copier 1 whichis the information source. This format ends with the time when thereport factor occurred as determined by the timepiece 188 of the controldevice 18. Regarding the data fields, while the kinds of data to be sentto the host machine 16 depend on the parameters set in the controldevice 18, FIG. 15B shows a specific condition wherein parameters areset such that only the number of times that an error has been found byself-diagnosis and the states of the copier are sent. The data formatshown in FIG. 15C is used for the control device 18 to send the resultof communication to the copier 1 on completing the communication withthe host machine 16.

FIG. 16 shows a data format for implementing, among the accesses fromthe host machine 16 to the copier 1, the access for executing the readprocessing. As shown, the host machine 16 sends to the control device 18a request code representative of read processing and a coderepresentative of an item to read after the type number and serialnumber of the copier 1. In response, the control device 18 removes thetype number and serial number fields from the received data format andsends only the read request code and item code to the copier 1. Thecopier 1 which receives such codes sends a read response code, thereceived item code, and then requested data to the control device 18.The control device 18 again adds the type number and serial number tothe codes and data received from the copier 1 and sends them to the hostmachine 16.

FIG. 17 shows a data format for implementing the write processing. Asshown, for a communication meant for the copier 1, data to write isadded to the item code described above in relation to the readprocessing. On the other hand, for a communication meant for the hostmachine 16, data actually written in the copier 1 is sent after the itemcode field. While the data to be written to the copier 1 and the data tobe sent from the copier 1 are expected to be identical, they will not beidentical when, for example, the received data exceeds a valid range andis rounded to a boundary value.

FIG. 18 shows a data format applicable to the execute processing. Inthis case, assume that a communication meant for the copier 1 cannotdesignate the object of operation with the item code alone. Then, a codefor supplementing the content of operation is sent after the item code.The copier 1 which performed the requested operation sends the result ofoperation to the host machine 16 via the control device 18.

FIGS. 19A-19C show data formats available for the host machine 16 toaccess the control device 18 and implementing the read processing, writeprocessing, and execute processing, respectively. The data formats ofFIGS. 19A-19C are essentially similar to the formats used for the accessto the copier 1 except that the type number and serial number arereplaced with a code representative of the control device 18.

FIG. 20 shows a data format with which the control device 18 accessesthe copier 1. As shown, the format of FIG. 20 is identical with, amongthe formats shown in FIGS. 16-18, the format implementing thecommunication between the control device 18 and the copier 1. Therefore,the copier 1 does not have to distinguish the accesses from the hostmachine 16 and can handle them in the same way.

FIG. 21 is a flowchart demonstrating a main routine for report controland executed by the CPU 100, FIG. 7, of the copier 1. As shown, assumethat the communication permit/inhibit switch 111 located outside theoperation board 70 of the copier is in an ON state. Then, when the CPU100 determines that the remote report key 83, FIG. 2, has been pressed,that an error has been found by self-diagnosis, or that a precaution isnecessary, it executes a corresponding remote report procedure.

FIG. 22 is a flowchart representative of a subroutine included in themain routine of FIG. 21 and relating to the remote report key 83. Asshown, the CPU 100 sends remote report data to the control device 18 inresponse to the operation of the key 83. When the report fails, e.g,when the control device 18 does not answer, the CPU 100 turns on theremote communication error indicator D8 on the operation board 70 orcauses it to blink to alert the user to the failure. When the data wassuccessfully sent to the control device 18, the CPU 100 resets a timeruse to determine a time over and then awaits the result of report fromthe control device 18. In the illustrative embodiment, when the resultof report is not received from the control device 18 within 3 minutes,the CPU 100 determines that time is over. Then, the CPU 100 again causesthe remote communication error indicator D8 to glow or blink. When theresult of report is received within 3 minutes, the CPU 100 determineswhether or not the report was successful by examining the result. If thereport was successful, the CPU 100 displays it graphically (although notshown); if otherwise, the CPU 100 causes the remote communication errorindicator D8 to glow or blink.

FIG. 23 shows a remote report subroutine also included in the mainroutine of FIG. 21 and relating to an error found by self-diagnosis. Asshown, this subroutine is identical with the subroutine of FIG. 22except that the data to be sent to the control device 18 is the dataassociated with self-diagnosis and that the time is determined to beover when 20 minutes expires.

FIG. 24 shows a remote report subroutine further included in the mainroutine of FIG. 21 and relating to a precaution. In this routine, theCPU 100 sends data for a precaution to the control device 18.

FIG. 25 is a flowchart demonstrating a main routine which the CPU 100executes when the control device 18 accesses the copier 1. As shown,assume that the interface unit 109 has received data while thecommunication permit/inhibit switch 111, FIG. 7, is in an ON state.Then, the CPU 100 determines the kind of processing or request, i.e.,read request, write request or execute request indicated by the firstfield of the data, and then executes corresponding processing. When thefirst field of received data does not indicate any one of the threekinds of request, the CPU 100 returns an error code and ends theprocedure.

FIG. 26 shows a read process subroutine included in the main routine ofFIG. 25. As shown, if the item code received by the copier 1 is corrector readable, the CPU 100 returns requested data; if otherwise, the CPU100 returns an error code.

FIG. 27 shows a write process subroutine also included in the mainroutine of FIG. 25. As shown, if the received item code is not corrector writable, the CPU 100 returns an error code. If the item code iscorrect, the CPU 100 checks the value to write and, if it lies in avalid range, writes the received data. If the value does not lie in thevalid range and if the item is of the kind allowing the data to berounded to the boundary value of the valid range, the CPU 100 writes theboundary value. If the item is not of the kind mentioned, the CPU 100sends an error code and then returns. Whether the data should be roundedor not depends on the item code. For example, the fixing temperature andthe telephone number of the service center are inhibited from beingrounded to the boundary value; the fixing temperature will have greatinfluence when rewritten, even if it lies in the valid range, while thetelephone number of the service center is meaningless in respect ofnumerical value. On the other hand, an auto reset time and other itemsof the kind not effecting image quality are allowed to be rounded. Whenthe auto reset time, for example, should be extended as far as possible,the maximum value available with the number of digits may be written;then, the copier 1 will select the maximum value automatically.

FIG. 28 shows an execute process subroutine further included in the mainroutine of FIG. 25. As shown, if the received item code is not corrector executable, the CPU 100 returns an error code. If the item code iscorrect, the CPU 100 determines whether or not the item needs asupplementary operation content and, if the answer is negative, executesthe designated operation, and then returns the result of operation. Ifthe item needs a supplementary content, the CPU 100 executes anoperation according to the supplementary information. At this instant,if the supplementary content does not lie in the valid range, the CPU100 sends an error code and returns.

FIG. 29 is a flowchart representative of control over the total countervalue communication shown in FIG. 12 and executed by the control device18. As shown, based on the previously stated timers (total countercontrol timers) included in the control device 18 and the collectiondate, transfer date and report date set in the control device 18, thecontrol device 18 executes total counter value collection control, totalcounter value transfer control, and total counter value report controlwhich will be described later.

FIG. 30 demonstrates control over the total counter value communicationshown in FIG. 13 and executed by the control device 18. As shown, whentotal counter transfer control is executed, total counter value reportcontrol is executed. Also, the total counter value transfer control isexecuted when total counter value collection control is executed or whenit is not executed even on the elapse of the transfer processing timeafter the total counter value transfer date set in the control device18. In the specific procedure, the transfer processing time is assumedto expire in 24 hours. The collection of total counter values isperformed on the basis of the timer installed in the control device 18.

FIG. 31 shows a total counter value collection control subroutineincluded in the procedure of FIGS. 29 or 30. As shown, the controldevice 18 sends a total counter value read request to the copier 1 andthen determines if the request was sent correctly or not. If thetransmission failed, e.g., when the copier 1 did not return a response,the program returns. If the transmission was successful, the controldevice 18 resets a timer, not shown, and then awaits a total countervalue from the copier 1. In the specific procedure, 1 minute is set inthe timer. When the control device 18 does not receive a total countervalue within 1 minute, the program returns determining that time isover. When the control device 18 receives it within 1 minute, the device18 writes it in the memory A, sets a total counter value collectionflag, sets the next date for collection, and then returns.

FIG. 32 shows a total counter value transfer control subroutine includedin the procedure of FIGS. 29 or 30. As shown, the control device 18reads total counter values out of the memory A, transfers them to thememory B, executes processing to be described sequentially, and thenreturns. The control device 18 writes the current date when the transferfrom the memory A to the memory B occurred in a date area (referred toas a memory C hereinafter) also provided in the RAM 186, FIG. 5.Subsequently, the control device 18 sets a total counter value transferflag, resets the total counter value collection flag, and then sets thenext date for collecting a total counter value.

FIG. 33 shows a total counter value report control subroutine alsoincluded in the procedure of FIGS. 29 or 30. As shown, assume that theswitch 189, FIG. 5, is in an ON state and allows total counter values tobe automatically sent to the host machine 16, and that a predeterminedreportable time has not expired after the set report date. Then, thecontrol device 18 sends the total counter values stored in the memory Bto the host machine 16. In the specific procedure, the reportable timeis assumed to be 24 hours. Subsequently, the control device 18determines whether or not the communication to the host machine 16 wassuccessful. If the communication was not successful, e.g., when the hostmachine 16 did not respond, the control device 18 returns. If thecommunication was successful, the control device 18 resets a timer andthen awaits the result of report from the host machine 16. In thespecific procedure, 20 minutes is set in the timer; if the controldevice 18 does not receive the result of report within 20 minutes, itreturns. When the control device 18 receives the result of report within20 minutes, it determines whether or not the result is acceptable. Ifthe result is acceptable, the control device 18 sets the next date forreporting total counter values to the host machine 16, resets the totalcounter value transfer flag, and then returns; if otherwise, it simplyreturns.

On the other hand, when the switch 189 is in an OFF state or when thepredetermined reportable time has expired after the set report date, thecontrol device 18 sets the next date for reporting total counter valuesto the host machine 16, as when the report was successful. Then, thecontrol device 18 resets the total counter transfer flag and returns.

FIG. 34 shows an initializing procedure to be executed by the controldevice 18. As shown, the control device 18 initializes the RAM andperipheral devices, determines whether or not the total counter valuetransfer date set therein has expired, and, if it has expired, executesthe previously stated total counter value transfer processing.

Hereinafter will be described a communication procedure between thecontrol device 18 and the copiers 1. FIG. 35 shows a communicationsequence in which five copiers 1 are connected to the control device 18,and the copiers 1 and device 18 are held in an idle state. As shown, thecontrol device 18 executes a polling cycle for transmitting a pollingsequence to the copiers 1 sequentially by use of the polling addressesof the copiers 1. When polled by its own address, the copier 1 sends anegative answer if a text to send is absent. Usually, the control device1 repeats this polling cycle so long as the communication processing isnot necessary.

FIG. 36 shows a specific communication sequence in which a copier withan address 2 has a text to send by remote report. As shown, after thecopier 2 has been addressed by its own address, it sends the text to theRS-485 line.

FIG. 37 shows a specific communication sequence in which the controldevice 18 sends a text representative of the result of report to acopier designated by an address 5. As shown, after completing pollingunder way, the control, device 18 sends a selecting sequence to thecopier 5 by using a selecting address assigned to the copier 5, sendsthe text to the copier 5, and then resumes the polling cycle.

FIG. 38 shows a communication sequence between the control device 18 anda copier with an address 3 to occur when the device 18 accesses thecopier 3. As shown, the control device 18 selects the copier 3, and thensends a text representative of a read request, write request or executerequest to the copier 3. Just after the transmission of the text, thecontrol device 18 polls the same copier 3 so as to receive a response tothe request. In practice, the sequence of FIG. 37 is inserted in thepolling cycle shown in FIG. 35.

FIG. 39 shows a specific communication sequence for implementing theperiodic transfer of total counter values. As shown, when the date forcollecting total counter values is reached, the control device 18inserts in the polling cycle a selecting cycle for selecting the copierswith addresses 1-5 sequentially. When any one of the copiers 1-5 returnsa response to the control device 18, the device 18 polls the same copier1 immediately so as to receive data (total counter value). In the nextselecting cycle, the control device 18 skips the copier 1 sent the datathereto. Specifically, in FIG. 39, the control device receives aresponse from the copiers 1, 3 and 4 in the first selecting cycle, andthen selects the copiers 2 and 5 which failed to send data in the nextselecting cycle. In the immediately following selecting cycle, thecontrol device 18 receives data from all the copiers 1-5 and thenresumes the polling cycle shown in FIG. 35.

FIG. 40 shows another specific communication sequence for implementingthe periodic transfer of total counter values. When the date forcollecting total counter values is reached, the control device 18selects the copiers 1-5 sequentially at the time when it would poll themin the procedure of FIG. 39, i.e., instead of polling them. When any oneof the copiers 1-5 responds to the selection, the control device 18polls it immediately to receive data. The first cycle to be executedwith the copiers 1-5 just after the date for total counter valuecollection is the same as in the procedure of FIG. 39. However, thefirst cycle is not followed by a polling cycle. Specifically, in thesecond cycle, the control device 18 polls only the copiers sent data tothe device 18 while selecting the other copiers to request them to sendcounter values. As soon as the control device 18 receives data from allthe copiers 1-5, the device 18 restores the usual state in which itexecutes polling only. In the specific procedure, as in the procedure ofFIG. 39, the control device 18 receives a response from the copiers 1, 3and 4 first, receives data from, among the copiers which failed to senddata, the copier 2 in the second cycle, and then successfully receivesdata from all the copiers 1-5 in the third cycle.

In summary, it will be seen that the present invention provides acommunication control device having various unprecedented advantages, asenumerated below.

(1) Assume that particular data of an image forming apparatus andupdated day by day should be read periodically. Then, even when thepower supply to the image forming apparatus is shut off, a host machinecan access the apparatus to read the data which should be readperiodically, and receive it. In addition, the data can be preserveduntil the next time for reading. For example, the image formingapparatus sends data to the control device once a day, while the controldevice sends data to the host machine at the time for adding up data(usually once a month). Further, assume that the control device has onlyone memory, and that a trouble of the kind needing two days to removehas occurred while a communication for adding up data is held betweenthe control device and the host machine. Then, since data after theadd-up of the data is also continuously sent to the memory of thecontrol device, the data before the add-up and the data after the add-upcannot be distinguished from each other and, therefore, cannot be addedup with accuracy. In light of this, the control device is provided withfirst storing means for storing data received from the image formingapparatus, and second storing means for storing data to be sent to thehost machine. With such two storing means, it is possible to distinguishthe data before add-up and the data after add-up.

(2) The control device connects a line to the host machine automaticallyand sends data thereto. Hence, even when the power supply to the imageforming apparatus is shut off, the host machine can receive particulardata without accessing it. Furthermore, when a line is connected fromthe image forming apparatus, the control device can be connected even toa telephone set of the type unable to be accessed by the host machinedirectly due to the operator's extension switching.

(3) The control device can send particular data of individual imageforming apparatuses to the host machine whenever needed. In addition,data reception is prevented from concentrating in a given period, sothat reception can be executed systematically.

(4) Particular data can be surely transferred from the first storingmeans to the second storing means.

(5) Assume that the power supply to the image forming apparatus is notturned on on the date or the time when particular data should betransferred in the control device. Then, the control device transfersparticular data received from the apparatus last time and sends them tothe host machine. As a result, the data sent to the host machine isclose to the data existing in the apparatus. For example, when the powersupply to the apparatus is not turned on on the date for transferringparticular data in the control device, the control device transfersparticular data received last time and, therefore, sends data close todata on the transfer date to the host machine.

(6) Particular data can be surely sent from the second storing means tothe host machine.

(7) The control device can surely determine if particular data iscorrect or not by reading the date or the time written from the hostmachine.

(8) When the control device calls the host machine to send particulardata thereto, an occurrence that the line cannot be connected to thehost machine due to the limited capacity of the host machine is reducedas far as possible. Hence, the host machine can execute receiveprocessing systematically.

(9) When the power supply to the apparatus is turned on after the dateor the time for the transfer of particular data has expired, particulardata received last time is transferred from the first storing means tothe second storing means. As a result, data close to data on thetransfer date or transfer time is sent to the host machine, minimizingthe error.

(10) The control device allows the host machine to read supervisorydata, which should be read out for maintenance periodically, at a remotestation without regard to the power supply to the apparatus.

(11) It is not necessary to install a plurality of control devices ateach user's station. This successfully saves cost and space.

Various modifications will become possible for those skilled in the artafter receiving the teachings of the present disclosure withoutdeparting from the scope thereof.

What is claimed is:
 1. A communication control device formed as a singlecomponent unit connected between an image forming apparatus and acommunication line in an image forming apparatus supervising systemwhich connects said image forming apparatus and a host machine by saidcommunication line, said device comprising:total counter value receivingmeans for receiving total counter value data from said image formingapparatus periodically; first storing means for storing said totalcounter value data received by said total counter value receiving means;and second storing means for storing said total counter value datatransferred from said first storing means, wherein said device beingcapable of reading said total counter value data out of said secondstoring means when connected to said host machine via said communicationline.
 2. A device as claimed in claim 1, further comprising settingmeans for setting a date or a time for transferring said total countervalue data from said first storing means to said second storing means.3. A device as claimed in claim 1, further comprising third storingmeans for storing a date or a time when said total counter value data istransferred from said first storing means to said second storing means.4. A device as claimed in claim 1, wherein said total counter value dataincludes supervisory data for a maintenance contract of said imageforming apparatus.
 5. A device as claimed in claim 1, wherein aplurality of image forming apparatuses are connectable to said device,said device further comprising control means for controllingcommunications of said plurality of image forming apparatuses with saidhost machine via said communication line.
 6. A communication controldevice formed as a single component unit connected between an imageforming apparatus and a communication line in an image forming apparatussupervising system which connects said image forming apparatus and ahost machine by said communication line, said device comprising:totalcounter value receiving means for receiving total counter value datafrom said image forming apparatus periodically; first storing means forstoring said total counter value data received by said total countervalue receiving means; second storing means for storing said totalcounter value data transferred from said first storing means; andtransmitting means for sending said total counter value data stored insaid second storing means to said host machine periodically.
 7. A deviceas claimed in claim 6, further comprising setting means for setting adate or a time for sending said total counter value data by saidtransmitting means.
 8. A device as claimed in claim 7, furthercomprising inhibiting means for inhibiting transfer of said totalcounter value data to said host machine on the elapse of a predeterminedperiod of time after said date or said time for said transmitting meansto send data to said host machine.
 9. A device as claimed in claim 7,further comprising setting means for setting a date or a time fortransferring said total counter value data from said first storing meansto said second storing means.
 10. A device as claimed in claim 6,further comprising setting means for setting a date or a time fortransferring said total counter value data from said first storing meansto said second storing means.
 11. A device as claimed in claim 10,wherein said total counter value receiving means comprises means forreceiving said total counter value data from said image formingapparatus during an interval between said date or said time for totalcounter value data transfer from said first storing means to said secondstoring means and a predetermined date or a predetermined time followingsaid date or said time, said device further comprising transferringmeans for transferring said total counter value data stored in saidfirst storing means to said second storing means.
 12. A device asclaimed in claim 11, further comprising transferring means fortransferring, when said total counter value data is not received fromsaid image forming apparatus within an interval between said date orsaid time for total counter value data transfer from said first storingmeans to said second storing means and a predetermined date or apredetermined time following said date or said time, said total countervalue data is transferred from said first storing means to said secondstoring means after said predetermined date or said predetermined time.13. A device as claimed in claim 11, further comprising means forcausing said total counter value data to be sent from said secondstoring means to said host machine when said total counter value data istransferred from said first storing means to said second storing means.14. An image forming apparatus supervising system having an imageforming apparatus and a host machine which are connected to each other,a communication line connecting said image forming apparatus and saidhost machine, and a communication control device formed as a singlecomponent unit connected between said image forming apparatus and saidcommunication line, said communication control device comprising:acommunication interface connected to said image forming apparatus toreceive total counter values from said image forming apparatus; a firstmemory connected to said communication interface to store said totalcounter values from said communication interface; and a second memoryconnected between said first memory and said communication line toreceive said total counter values from said first memory and store saidtotal counter values, wherein said communication control device beingcapable of reading said total counter values out of said second memoryand sending said total counter values to said host machine via saidcommunication line.
 15. A communication control device as claimed inclaim 14, wherein data is transferred from said first memory to saidsecond memory at substantially a same time as data is sent from saidsecond memory to said host machine.
 16. A communication control deviceas claimed in claim 14, wherein said image forming apparatus comprises acopier.
 17. A communication control device as claimed in claim 14,wherein a sending period from the second memory to the host machine isselected such that the sending occurs after a transfer of said totalcounter values from the first memory to the second memory, but before anext transfer from the first memory to the second memory.
 18. Acommunication control device formed as a single component unit connectedbetween an image forming apparatus and a communication line in an imageforming apparatus supervising system which connects said image formingapparatus and a host machine by said communication line, saidcommunication control device comprising:total counter values receivingmeans for receiving total counter values from said image formingapparatus periodically; first storing means for storing said totalcounter values received by said total counter values receiving means;second storing means for storing said total counter values transferredfrom said first storing means; and setting means for setting a date or atime for automatically transferring said total counter values from saidfirst storing means to said second storing means on the set date ortime, wherein said device being capable of reading said total countervalues out of said second storing means and sending said total countervalues to said host machine via said communication line.
 19. Acommunication control device as claimed in claim 18, wherein data istransferred from said first storing means to said second storing meansat substantially a same time as data is sent from said second storingmeans to said host machine.
 20. A communication control device asclaimed in claim 18, wherein said image forming apparatus comprises acopier.
 21. A communication control device as claimed in claim 18,further comprising third storing means for storing a date or a time whensaid total counter values are transferred from said first storing meansto said second storing means.
 22. A communication control device asclaimed in claim 18, wherein a plurality of image forming apparatusesare connectable to said device, said device further comprising controlmeans for controlling communications of said plurality of image formingapparatuses with said host machine via said communication line.
 23. Acommunication control device as claimed in claim 18, wherein a sendingperiod from the second storing means to the host machine is selectedsuch that the sending period occurs after a transfer of said totalcounter values from the first storing means to the second storing means,but before a next transfer from the first storing means to the secondstoring means.